获得DateTemplate中的element

比较困难的是用DataTemplate.FindName(string name,parent),需要知道这个datatemplate visual tree中的直系父亲，只要就是查找这个父亲了。

例子：

<DataTemplate x:Key="myDataTemplate">
  <TextBlock Name="textBlock" FontSize="14" Foreground="Blue">
    <TextBlock.Text>
      <Binding XPath="Title"/>
    </TextBlock.Text>
  </TextBlock>
</DataTemplate>
ItemsControl通过ItemContainerGenerator产生items, 从一个dataItem到visual tree item,能够用ItemContainerGenerator.ContainerFromIndex 或者 ItemContainerGenerator.ContainerFromItem获得一个 container,如一个TreeViewItem.相反还有ItemContainerGenerator.ContainerFromItem,ItemContainerGenerator.ItemFromContainer方法来从container获得index或者dataItem.

重新转到获得dataTemplate, 例子：

// Getting the currently selected ListBoxItem
// Note that the ListBox must have
// IsSynchronizedWithCurrentItem set to True for this to work
ListBoxItem myListBoxItem =
(ListBoxItem)(myListBox.ItemContainerGenerator.ContainerFromItem(myListBox.Items.CurrentItem));
// Getting the ContentPresenter of myListBoxItem
ContentPresenter myContentPresenter = FindVisualChild<ContentPresenter>(myListBoxItem);
// Finding textBlock from the DataTemplate that is set on that ContentPresenter
DataTemplate myDataTemplate = myContentPresenter.ContentTemplate;
TextBlock myTextBlock = (TextBlock)myDataTemplate.FindName("textBlock", myContentPresenter);
// Do something to the DataTemplate-generated TextBlock
MessageBox.Show("The text of the TextBlock of the selected list item: "
+ myTextBlock.Text);

FindVisualChild方法：

private childItem FindVisualChild<childItem>(DependencyObject obj)
where childItem : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child != null && child is childItem)
return (childItem)child;
else
{
childItem childOfChild = FindVisualChild<childItem>(child);
if (childOfChild != null)
return childOfChild;
}
}
return null;
}

 参考：

http://msdn.microsoft.com/en-us/library/system.windows.controls.itemscontrol.aspxhttp://msdn.microsoft.com/en-us/library/bb613579.aspx